METHOD FOR PREPARING POLYMERIC MATERIALS COMPRISING ONE OR SEVERAL METAL ELEMENTS

Abstract

The invention relates to a method for preparing a polymeric material doped with at least one first metal element and at least one second metal element, said at least one first metal element and said at least one second metal element being identical or different from each other, said method comprising: a) a step for copolymerization of at least one first monomer comprising at least one first metal element and of at least one second monomer comprising at least one chelating group of at least one second metal element, in return for which a polymeric material is obtained comprising recurrent units from the polymerization of said first monomer, said recurrent units comprise said at least one first metal element and comprising recurrent units from the polymerization of said second monomer, said recurrent units comprising chelating groups of at least one second metal element; and when said first metal element is different from said second metal element, said method further comprising a step b) for putting the material obtained in step a) in contact with a solution comprising said at least second metal element, in return for which said at least second metal element is complexed with the aforementioned chelating groups, this step b) being optional when said first metal element and said second metal element are identical.

Claims

1: A method for preparing a polymeric material doped with at least one first metal element and at least one second metal element, said at least one first metal element and said at least one second metal element being identical or different from each other, said method comprising: a) copolymerization of at least one first monomer comprising at least one first metal element and of at least one second monomer comprising at least one chelating group of at least one second metal element, to obtain a polymeric material comprising recurrent units deriving from the polymerization of said first monomer, said recurrent units comprising said at least one first metal element and comprising recurrent units deriving from the polymerization of said second monomer, said recurrent units comprising chelating groups of at least one second metal element, to obtain a material a); and when said first metal element is different from said second metal element, said method further comprising a step b) contacting the material a) with a solution comprising said at least second metal element, in order to complex said at least second metal element with the aforementioned chelating groups, wherein the contacting b) is optional when said first metal element and said second metal element are identical.

2: The method for preparing a material according to claim 1, wherein, when said at least one first metal element and said at least one second metal element are identical, the method does not comprise the contacting b).

3: The method for preparing a material according to claim 1, wherein, when said at least one first metal element and said at least one second metal element are different, the method comprises the copolymerization a) and the contacting b).

4: The method for preparing a material according to claim 1, wherein the first monomer is an ethylenic monomer comprising at least one aromatic group to which is bound a group bearing at least one first metal element.

5: The method for preparing a material according to claim 1, wherein the first monomer satisfies formula (I): ##STR00013## wherein: R.sub.1 is an ethylenic group; and R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 represent, independently of each other, a hydrogen atom, an OH group, an amine group, a CHO group, an oxime group, a hydrazone group, a carboxyl group COOH, a halogen atom, a trialkylsilane group, a -M-L group with M being the first metal element and L being a phosphine group, and the optional salts thereof, provided that least one of the groups R.sub.2 to R.sub.6 represent a -M-L group as defined above.

6: The method for preparing a material according to claim 1, wherein the first monomer is the monomer of the following formula (II): ##STR00014## with M being Au or In and L being a triethylphosphine group or a triphenylphosphine group.

7: The method for preparing a material according to claim 1, wherein the second monomer comprises at least one group bearing a free doublet.

8: The method for preparing a material according to claim 1, wherein the second monomer is a cyclic monomer comprising at least one nitrogen-containing group selected from among: an aromatic monomer comprising an oxime group; a monomer comprising an alicyclic amine group; and a heteroaromatic monomer comprising one or more nitrogen atoms.

9: The method for preparing a material according to claim 1, wherein the second monomer is a monomer of the following formula (III): ##STR00015## wherein: R.sub.7 is an ethylenic group; and R.sub.8, R.sub.9, R.sub.10, R.sub.11 and R.sub.12 represent, independently of each other, a hydrogen atom, an OH group, an amine group, a CHO group, an oxime group, a hydrazone group, a carboxyl group COOH, a halogen atom, a trialkylsilane group, and the optional salts thereof, provided that at least one of the groups R.sub.8 to R.sub.12 represents an OH group and at least one of the groups R.sub.8 to R.sub.12 represents an oxime group.

10: The method for preparing a material according to claim 9, wherein the second monomer is a monomer of the following formula (IV): ##STR00016##

11: The method for preparing a material according to claim 8, wherein the second monomer is a monomer of the following formula (V): ##STR00017## wherein: R.sub.13, R.sub.14 and R.sub.15 represent a styrenic group; and p, q, r, x are integers ranging from 0 to 20, provided that, when x is equal to 0, (r+q) is at least equal to 2, and when x is equal to 1, at least one of p, q, r is different from 0.

12: The method for preparing a material according to claim 11, wherein the second monomer is a monomer of the following formula (VI): ##STR00018##

13: The method for preparing a material according to claim 8, wherein the second monomer is a vinylimidazole monomer fitting the following formula (VII): ##STR00019##

14: The method for preparing a material according to claim 1, wherein the copolymerization a) occurs in the presence of one or more comonomers.

15: The method according to claim 14, wherein the one or more comonomers are selected from the group consisting of a styrenic monomer and an acrylate monomer.

16: The method according to claim 14, wherein the one or more comonomer comprises at least two ethylenic groups.

17: The method according to claim 14, wherein the one or more comonomer is represented by one of the following formulae (VIII) or (IX): ##STR00020## wherein the (6-n) R.sub.16 groups either identical or different, represent a hydrogen atom, an alkyl group, an aryl group, an O-aryl group, an O-alkyl group, an acyl group, an alkylaryl group or a halogen atom, said alkyl, aryl, alkylaryl, O-aryl, O-alkyl groups being optionally perfluorinated and n is an integer ranging from 1 to 3; ##STR00021## wherein R.sub.17 represent an alkyl group, R.sub.18 represent H or an alkyl group and n being an integer ranging from 1 to 3.

18: The method according to claim 17, wherein the comonomer is divinylbenzene.

19: The method according to claim 1, wherein the copolymerization a) occurs in the presence of at least one polymerization initiator.

20: The method according to claim 1, wherein the copolymerization a) occurs in the presence of a pore-forming solvent, which is a polar, apolar organic solvent selected from the group consisting of an ether solvent, dimethylsulfoxide, a phthalate solvent, an alcoholic solvent, an aromatic solvent, a ketone solvent and mixtures thereof.

21: The method according to claim 1, wherein the copolymerization a) occurs with a monomer of formula (II): ##STR00022## with M being Au and L being a triethylphosphine group, a monomer of formula (VII): ##STR00023## and divinylbenzene.

22: The method according to claim 1, wherein the contacting b) comprises contacting the material a) with a solution comprising said at least second metal element, to obtain said at least second metal element complexed with the chelating groups.

23: The method according to claim 1, further comprising drying the material a) or a material obtained in the contacting b).

24: The method according to claim 23, wherein the drying is a supercritical drying.

25: The method according to claim 1, wherein the first metal element is gold and the second metal element is copper.

26: The method according to claim 1, wherein the polymeric material is a foam.

27: A polymeric material obtained by the method of claim 1, wherein the polymeric material is doped with at least one metal element.

28: An element of a laser target, the element comprising the polymeric material of claim 27.

Description

DETAILED DISCUSSION OF PARTICULAR EMBODIMENTS

Example 1

[0102] The present example illustrates the synthesis of a polymeric foam doped with gold according to the invention.

[0103] To do this, three steps are applied: [0104] a step for synthesis of a metal monomer (step a); [0105] a step for polymerization of said monomer in the presence of another complexing monomer and complexation of the resulting material (step b); [0106] a step for drying the resulting material in order to form a foam (step c).

[0107] a) Synthesis of a Metal Monomer

[0108] This step more specifically relates to the preparation of a metal monomer fitting the following formula:

##STR00012##

wherein Et corresponds to an ethyl group, this monomer being subsequently designated as StyAuPEt.sub.3.

[0109] To do this, p-bromostyrene (0.75 g) is solubilized in tetrahydrofurane (8 mL) in a Schlenk tube under an inert atmosphere. After having cooled the contents of the tube to 80 C., butyllithium (1.62 mL) is added. To the resulting solution, is added drop wise gold chlorotriethylphosphine CIAuPEt (1 g) solubilized beforehand in tetrahydrofurane (16 mL). The resulting mixture is maintained, with stirring at 80 C. for 1 hour and then the temperature gradually rises up to room temperature. Stirring is maintained overnight. The mixture is then hydrolyzed, at a temperature of 0 C., with a saturated ammonium chloride solution (20 mL) and then this mixture is subject to extraction with diethyl ether (20 mL) twice. The collected organic phases are washed with a saturated sodium chloride solution (15 mL) and then dried with sodium sulfate before being evaporated by rotation in vacuo. The resulting product is kept at 4 C.

[0110] It corresponds to the monomer of the formula explicated above, as confirmed by the .sup.1H NMR, .sup.13C NMR and .sup.31P NMR results below.

[0111] .sup.1H NMR (THF-d8): (ppm): 1.22 (9H.sub.8, m, J=7 Hz); 1.80 (6H.sub.7, q, J=7 Hz); 5.11 (1H.sub.6, dd, J=11/1.2 Hz); 5.69 (1H.sub.6, dd, J=17.6/1.2 Hz); 6.69 (1H.sub.5, dd, J=11/17.6 Hz); 7.33 (2Har, d, J=7.8 Hz); 7.49 (2Har, d, J=7.8 Hz)

[0112] .sup.13C NMR (THF-d8): (ppm): 8.9 (3C.sub.8); 17.8 (3C.sub.7, d, J=30 Hz); 111.3 (C.sub.6); 125.0 (2C.sub.3); 134.4 (C.sub.4); 137.8; 139.2 (2C.sub.2 or 1C.sub.5); 175.9 (C.sub.1, d, J=116 Hz)

[0113] .sup.31P NMR (THF-d8): (ppm): 42

[0114] b) Polymerization of Said Monomer in the Presence of Another Complexing Monomer

[0115] In a flask, the monomer StyAuPtEt.sub.3 prepared in step a) (0.1232 g) is solubilized in tetrahydrofurane (1 mL). A complexing monomer, 1-vinylimidazole (designated as VI) (0.1232 g), an initiator, azobisisobutyronitrile (0.0308 g), a cross-linking agent, divinylbenzene (0.0616 g) and a pore-forming solvent, diethyl phthalate (6 mL) are added to the solubilized monomer StyAuPtEt.sub.3. The solution is degassed in argon for 3 minutes. It is then injected into molds, which are placed in an inert chamber. The polymerization reaction is carried out at 60 C. for 24 hours. The resulting gels are then removed from the mold in an ethanol solution. The ethanol is changed three times, in order to remove the diethyl phthalate and tetrahydrofurane.

[0116] The gels are then immersed in a solution (18 mL) comprising a gold salt HAuCl.sub.4.3H.sub.2O (Au: 8.9 mg/mL) for a period of 7 days. The gels are then subject to mechanical stirring.

[0117] c) Drying of the Material

[0118] The gels are then dried, in an autoclave, by supercritical drying with CO.sub.2, for which the cycle of pressures and temperatures is the following: 50 C. at 180 bars for 30 hours with a CO.sub.2 flow rate of 2.5 kg.Math.h.sup.1. The negative pressure of the autoclave is then achieved at 50 C. at 0.5 bars.Math.min.sup.1 down to room temperature.

Example 2

[0119] This example relates to the preparation of a polymeric foam doped with gold and with copper according to the invention.

[0120] To do this, two steps are applied: [0121] a step for polymerization of the monomer StyAuPEt.sub.3 in the presence of another complexing monomer and of complexing of the resulting material (step b); [0122] a step for drying the resulting material in order to form a foam (step c).

[0123] a) Polymerization of the Monomer StyAuPEt.sub.3 in the Presence of Another Complexing Monomer and Complexation of the Resulting Material

[0124] In a flask, the monomer StyAuPtEt.sub.3 (0.1232 g) is solubilized in tetrahydrofurane (1 mL). A complexing monomer, 1-vinylimidazole (designated as VI) (0.1232 g), an initiator, azobisisobutyronitrile (0.0308 g), a cross-linking agent, divinylbenzene (0.0616 g) and a pore-forming solvent, diethyl phthalate (6 mL) are added to the solubilized monomer StyAuPtEt.sub.3. The solution is degassed in argon for 3 minutes. It is then injected into molds, which are placed in an inert chamber. The polymerization reaction is conducted at 60 C. for 24 hours. The resulting gels are then removed from the mold in an ethanol solution. The ethanol is changed three times, in order to remove diethyl phthalate and tetrahydrofurane.

[0125] The gels are then immersed in a solution (18 mL) comprising a copper salt CuCl.sub.2 (Cu: 8.9 mg/mL) for a period of 24 hours. The gels are then subject to mechanical stirring.

[0126] The gel is then washed three times in ethanol after immersion in the copper solution.

[0127] b) Drying of the Material

[0128] The gels are then dried, in an autoclave, by supercritical drying with CO.sub.2, for which the cycle of pressures and temperatures is the following: 50 C. at 180 bars for 30 hours with a CO.sub.2 flow rate of 2.5 kg.Math.h.sup.1. The negative pressure of the autoclave is then achieved at 50 C. at 0.5 bar.Math.min.sup.1 down to room temperature.

Example 3

[0129] This example has the purpose of demonstrating the capability of the method of the invention of allowing optimization of the metal element content in a polymeric material but also, to a certain extent, the structural properties of the material.

[0130] To do this, two comparative tests were applied (tests a) and b) below), for which the specific gravity p (in mg/cm.sup.3) and the gold content (in % by mass) were respectively measured, so as to be able to compare these values with those obtained with the material obtained in Example 1.

[0131] The operating procedures for preparing the materials of tests a) and tests b) are illustrated below.

[0132] a) Test a

[0133] The present example illustrates the synthesis of a polymeric foam doped with gold obtained by copolymerization of the monomer StyAuPEt.sub.3 with divinylbenzene (respectively 50% by mass of StyAuPEt.sub.3 and 50% by mass of divinylbenzene).

[0134] To do this, the metal monomer StyAuPt.sub.3 (0.154 g) is solubilized with THF (2 mL). The initiator (AiBN, 0.0308 g), the cross-linking agent divinylbenzene (0.154 g) and the pore-forming solvent diethyl phthalate (6 mL) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is carried out at 60 C. for 24 hours. The gels are then removed from the molds in an ethanol solution. The ethanol is changed three times in order to remove the DEP and THF. Next, the gels are dried via a supercritical route with CO.sub.2.

[0135] The obtained foam has a specific gravity p of 522 (in mg/cm.sup.3) and a gold content of 10.10.4 (in % by mass).

[0136] b) Test b

[0137] The present example illustrates the synthesis of a polymeric foam doped with gold obtained by copolymerization of the monomer VI with divinylbenzene (respectively 50% by mass of monomer VI and 50% by mass of divinylbenzene) followed by impregnation with a gold salt.

[0138] To do this, in a flask, the complexing monomer 1-vinylimidazole (VI, Sigma Aldrich) (0.154 g), the initiator (AIBN, 0.0308 g), the cross-linking agent divinylbenzene (DVB, 0.154 g) and the pore-forming solvent diethylphthalate (DEP, 6 mL, Sigma Aldrich) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is conducted at 60 C. for 24 hours. The gels are then removed from the molds in an ethanol solution. The ethanol is changed three times in order to remove the DEP. Next, the gels are immersed in a gold solution (HAuCl.sub.4 in ethanol (18 mL), Au=8.9 mg/mL) for 7 days. The resulting gels are then washed three times with ethanol and then dried via a supercritical route with CO.sub.2.

[0139] The obtained foam has a specific gravity p of 894 (in mg/cm.sup.3) and a gold content of 261 (in % by mass).

[0140] As a comparison, the foam obtained in Example 1 according to the method of the invention has a specific gravity p of 714 (in mg/cm.sup.3) and a gold content of 34.41.4 (in % by mass).

[0141] Thus, the association of a metal monomer and of a complexing monomer according to the conditions of the method of the invention gives the possibility of optimizing the properties of the resulting material. More specifically, within the scope of the synthesis of polymeric foams based on gold, the association of the metal monomer StyAuPEt.sub.3 with the complexing monomer VI gives the possibility of increasing the metal element content relatively to that obtained with the material of the test a) and that of the test b). Further, the method of the invention gives the possibility of obtaining massive materials having a high metal content and a lower specific gravity than the one obtained with the material obtained with the metal monomer of test a) and greater than the one obtained with the material obtained with the complexing monomer of test b). Thus, the method of the invention allows optimization of the metal element content but also to a certain extent allows control of the structural properties of the material.

Example 4

[0142] This example has the purpose of demonstrating the capability of the method of the invention of giving the possibility of obtaining mechanically reinforced materials as compared with materials made without the impregnation step according to the invention.

[0143] To do this, two tests were applied: [0144] a comparative test (test a) not compliant with the invention illustrating the preparation of a foam obtained, inter alia, by copolymerization of StyAuPEt.sub.3 and of the monomer VI; [0145] a test according to the invention (test b) for preparing a foam obtained, inter alia, by copolymerization of StyAuPEt.sub.3 and of the monomer VI followed by impregnation with a gold salt.

[0146] The operating procedures for preparing the materials of tests a) and of tests b) are illustrated below.

[0147] a) Test a

[0148] The present example illustrates the synthesis of a polymeric foam obtained by a method not compliant with the invention, by copolymerization of the StyAuPEt.sub.3 monomer with divinylbenzene.

[0149] To do this, in a flask, the metal monomer StyAuPEt.sub.3 (0.1232 g) is solubilized with THF (2 mL, Sigma Aldrich). The complexing monomer 1-vinylimidazole (VI, Sigma Aldrich) (0.1232 g), the initiator (AIBN, 0.0308 g), the cross-linking agent divinylbenzene (DVB, 0.0616 g) and the pore-forming solvent diethylphthalate (DEP, 6 mL, Sigma Aldrich) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is conducted at 60 C. for 24 hours. The gels are then removed from the molds in an ethanol solution. The ethanol is changed three times in order to remove the DEP. The resulting gels are then dried via a supercritical route with CO.sub.2.

[0150] The obtained foam, after supercritical drying with CO.sub.2, has a poor mechanical strength, which is notably materialized by a deformation of the latter during the drying. Further, the obtained foam may easily be broken.

[0151] b) Test b

[0152] The present example illustrates the synthesis of a polymeric foam according to the invention.

[0153] To do this, in a flask, the metal monomer StyAuPEt.sub.3 (0.1232 g) is solubilized with THF (2 mL, Sigma Aldrich). The complexing monomer 1-vinylimidazole (VI, Sigma Aldrich) (0.1232 g), the initiator (AIBN, 0.0308 g), the cross-linking agent divinylbenzene (DVB, 0.0616 g), the pore-forming solvent diethylphthalate (DEP, 6 mL, Sigma Aldrich) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is conducted at 60 C. for 24 hours. The gels are then removed from the mold in an ethanol solution. The ethanol is changed three times in order to remove the DEP. Next, the gels are immersed in a gold solution (HAuCl.sub.4 in ethanol (18 mL), Au=8.9 mg/mL) for 7 days. The resulting gels are then washed three times with ethanol and then dried via a supercritical route with CO.sub.2.

[0154] At the end of the supercritical drying with CO.sub.2, the obtained foam is slightly deformed, which confirms its better mechanical strength, which may be ascribed to the complexation of the silver salt by the recurrent units stemming from the polymerization of the monomer VI.

[0155] Because of its better mechanical strength, the foam is thus be more easily handled.

Example 5

[0156] This example has the purpose of demonstrating the capability of the method of the invention of allowing optimization of the metal element content by means of the presence of the complexing monomer.

[0157] To do this, three tests were applied (tests a), b) and c) below), for which the theoretical gold content was determined (in % by mass) and for which the gold content (in % by mass) was measured.

[0158] The operating procedures for preparing the materials of tests a), b) and c) are illustrated below.

[0159] a) Test a

[0160] The present example illustrates the synthesis of a polymeric foam obtained by polymerization of the monomer StyAuPEt.sub.3 and of divinylbenzene (50% by mass of each of the monomers)

[0161] To do this, in a flask, the metal monomer StyAuPEt.sub.3 (0.154 g) is solubilized with THF (1 mL, Sigma Aldrich). The initiator (AIBN, 0.0308 g), the cross-linking agent divinylbenzene (DVB, 0,154 g), the pore-forming solvent diethylphthalate (DEP, 6 mL, Sigma Aldrich) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is conducted at 60 C. for 24 hours. The gels are then removed from the molds in an ethanol solution. The ethanol is changed three times in order to remove the DEP and the THF. Next, the gels are dried via a supercritical route with CO.sub.2.

[0162] The obtained foam, after supercritical drying with CO.sub.2, has an Au content of 123 (in % by mass), while the theoretical Au content was estimated to be 23 (in % by mass). [0163] b) Test b

[0164] The present example illustrates the synthesis of a polymeric foam according to the invention (respectively 40% by mass of StyAuPEt.sub.3, 40% by mass of monomer VI and 20% by mass of divinylbenzene).

[0165] To do this, in a flask, the metal monomer StyAuPEt.sub.3 (0.1232 g) is solubilized with THF (2 mL, Sigma Aldrich). The complexing monomer 1-vinylimidazole (VI, Sigma Aldrich) (0.1232 g), the initiator (AIBN, 0.0308 g), the cross-linking agent divinylbenzene (DVB, 0.0616 g), the pore-forming solvent diethylphthalate (DEP, 6 mL, Sigma Aldrich) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is conducted at 60 C. for 24 hours. The gels are then removed from the molds in an ethanol solution. The ethanol is changed three times in order to remove the DEP. The resulting gels are then dried via a supercritical route with CO.sub.2.

[0166] The obtained foam, after supercritical drying with CO.sub.2, has an Au content of 21.20.8 (in % by mass), while the theoretical Au content was estimated to be 19 (in % by mass).

[0167] b) Test c

[0168] The present example illustrates the synthesis of a polymeric foam according to the invention (respectively 50% by mass of StyAuPEt.sub.3, 39% by mass of monomer VI and 11% by mass of divinylbenzene).

[0169] To do this, in a flask, the metal monomer StyAuPEt.sub.3 (0.154 g) is solubilized with THF (2 mL, Sigma Aldrich). The complexing monomer 1-vinylimidazole (VI, Sigma Aldrich) (0.1232 g), the initiator (AIBN, 0.0308 g), the cross-linking agent divinylbenzene (DVB, 0.0308 g), the pore-forming solvent diethylphthalate (DEP, 6 mL, Sigma Aldrich) are added. The solution is degassed in argon for 3 minutes. It is injected into molds which are placed in an inert chamber. The polymerization is conducted at 60 C. for 24 hours. The gels are then removed from the molds in an ethanol solution. The ethanol is changed three times in order to remove the DEP. The resulting gels are then dried via a supercritical route with CO.sub.2.

[0170] The obtained foam, after supercritical drying with CO.sub.2, has an Au content of 220.9 (in % by mass), while the theoretical Au content was estimated to be 24 (in % by mass).

[0171] As a conclusion to these tests, it may be inferred that the presence of the complexing monomer VI in the application of the method of the invention gives the possibility of optimizing, without any impregnation step, the metal monomer content. The result of this is that the gold content in the material is close to the theoretical content. Without being bound by theory, this may be ascribed to the fact that the complexing monomer by establishing coordination bonds with the gold comprised in the metal monomer allows better incorporation of the metal monomer in the resulting material.